1. Field of the Invention
This invention relates to a mixture of polycyclic, aromatic polycarboxylic acids carrying nuclear nitro groups that is substantially soluble in a mixture of polar solvents but substantially insoluble in water and a process for preparing the mixture of polycyclic, aromatic polycarboxylic acids.
2. Description of Prior Art
In U.S. Pat. No. 4,052,448 to J. G. Schulz and E. T. Sabourin there is disclosed a mixture of polycyclic, aromatic polycarboxylic acids carrying nuclear nitro groups that is substantially soluble in a polar solvent but substantially insoluble in water and a process for preparing the mixture.